2010 Prius bought in July of 2009. Similar problem to what is currently being investigated. When coming to a stop (usually from highway speed) on a road with potholes, the car will hit a pothole and will lurch forward, as if I had taken my foot off of the brake. So far, continued pressure on the brake pedal has always stopped me in time.

- Ankeny, IA, USA

I own a 2010 Prius and when stopping going over a reasonable 'bump' the brakes seem to disengage so you get an acceleration feeling which causes you to react and press the brake again. It shakes you when is happens because you don't know what will happen!

- Milwaukee, WI, USA

I have a 2010 Prius and I have experienced frequent braking loss when driving over bumps while braking. The brakes release momentarily. I have experienced this many times!! it is definitely dangerous.

- Los Angeles, CA, USA

My brakes quit working if a brake on loose gravel or when I hit a bump at low speeds. Seems like the ABS is trying to work but fails to kick on.

- Clovis, CA, USA

2010 Prius - confirming reports about brake failure. At the company I work, there are rumble strips leading to a gate when departing the grounds. I have learned to slow way down before hitting the rumble strips because I almost hit the bar that rises at the gate the first few times after purchasing the car last summer (2009). The brakes briefly fail then kick in again. Have not been on rough terrain but I'm sure this would occur similar to the rumble strips.

- Middlefield, CT, USA

2010 Toyota Prius brake problem. This occurs when hitting a brake when on some sort of rough road area, like a pothole or a bump. It feels like either the brake isn't engaging or it's speeding up. It's hard to tell. Either way, it's scary and it can cause an accident. For instance, if you're driving in manhattan and you hit a pothole as you brake with a car in front of you. (I was lucky when this problem kicked in and I hit that pothole as there was no car in front of me at the time.) this problem has happened to me close to 10 times now. Please note that this has happened numerous times. It happened within a couple days of when I got the car. I didn't see "brakes" on your list of parts that were defective. I did see "service brakes" in 3 categories, but I didn't know if "service brakes" was some special meaning, nor did I know which kinds of brakes had the problem (or even which kind the car has).

- Belleville, NJ, USA

I have noticed the temporary loss of braking in my brand new 2010 Toyota Prius purchased in December 2009. When braking on uneven ground, if you hit a pothole in the road the car lurches forward and it feels like you hit the accelerator. Please encourage Toyota to address this issue.

- Sand Springs, OK, USA

2010 Prius with ABS problem. On uneven surfaces (I.e. potholes) or icy roads I have not had 3 events where the brakes were not effective. One situation was so bad and almost caused a serious accident under snow/icy conditions that I brought the car to Toyota immediately. I have a service record of that in mid December 2009. The service department kept my vehicle for a couple days and did icy road testing but never fully recreated the situation. I have documentation from the service department on this despite their not acknowledging a problem. I have a lot of recollection of the details leading up to the 3 scenarios that have occurred now and can likely give good insight. Btw, from the stories I read today in the press I think Toyota (and the stories) have the problem mostly described. I still have other concerns based on my experiences from the 3 events.

- Plainfield, IL, USA

The contact owns a 2010 Toyota Prius. The vehicle lunged forward and accelerated while the contact was driving approximately 20 mph and attempting to engage the brake pedal. The vehicle was diagnosed by the dealer who confirmed that it responded normally since the electrical engine switched over to the gasoline engine. The contact observed that the malfunction occurred continuously. The VIN was not available. The failure mileage was 17,000.

- Jefferson City, MO, USA

I am the owner of a 2010 Toyota Prius purchased new on January 21, 2010. Car has about 400 miles on the odometer. On February 2, 2010 while attempting to stop at a stop sign, traveling at a slow rate of the speed, the brakes failed to stop the car. After several attempts to apply the brakes, they finally stopped the car narrowly missing cross traffic. The pavement was smooth and speed was less than 25mph.

- Glendale, CA, USA

I own a 2010 Prius purchased in July 2009. I have also (regularly) felt a surge forward when braking and hitting a bump or pothole. Based on my readings of chat boards I thought this was normal, although it is quite alarming when it happens. I'm not confident that my local Toyota dealer would be entirely honest; when I was in for service during the floormat brake recall I overheard a service manager telling a customer it was nothing to worry about; it was only when people put non-manufacturer's floormats on top of the Toyota ones that there was a problem (which is not my understanding). I'd like to be kept informed of the status of the investigation if at all possible. I'll put in early August as the "incident date" but it happens regularly (at least once a week?)

- Concord, MA, USA

On my 2010 Toyota Prius II (purchased 9/30/2009, I have noticed on multiple occasions that while I am braking, if I hit a pothole, bump or rough pavement of some type, the braking suddenly releases for half-A-second or a second. I am maintaining pressure on the brake pedal but with a bump, it stops braking momentarily. Because I tend to give myself a lot of room to brake, none of these incidents has led to an accident, but it is very disconcerting.

- Takoma Park, MD, USA

I have experienced braking issues with a 2010 Prius purchased in July '09. While braking on ice or snow when first depressing the brake pedal for light braking nothing happens, no braking. When then depressing the brake pedal more firmly braking then starts suddenly but more aggressive than desired. This problem occurs on ice or snow only but I have not driven on extreme washboard or gravel roads. I have had the experience more than once and have begun to anticipate it happening regularly on ice or snow.

- Fort Collins, CO, USA

Prius 2010 "skidded" at slow speed on cold roadway twice. Just purchased the car in October.

- Washington, DC, USA

I have had my 2010 Prius for about 45 days, and on three occasions while traveling over bumpy surfaces and very firmly applying the brakes, I noticed a lack of stopping power for about half a second right after I hit a bump. They weren't tiny bumps, but they weren't craters either. The traction of my tires did not seem to be impaired. It felt like the brakes just let off for a fraction of a second.

- Dallas, TX, USA

Toyota Prius 2010. Problem reported to dealer 12-18-2010. Brakes become inoperative when passing over uneven surfaces, vehicle also at this time vehicle lurches forward. This occurs frequently. Contrary to your form requirements there is no one "approximate incident date". shifter sometimes is difficult to put into neutral, rather it will instead go from drive to reverse. If there is also a sudden acceleration problem, this could be a big problem when trying to regain control.

- Needham, MA, USA

I've experience braking problems with my 2010 Prius. As others have reported I too have had at least a dozen incidents in which I am applying the brakes and there is either a bump in the road or more often a pothole. Usually this has been when I was approaching a stop sign and braking moderately. The experience is such that the brakes seem to disengage at the time in which I hit the pothole or bump and the car lurches forward for just a split second. To me it feels like going over an ice patch and the sensation is similar to hydroplaning as well. This has not caused any accident but does contribute to a feeling of lose of control and causes you to possibly stop a little later than you intended to. I have 10,000 miles on this car and have had it since August 2009. I also experience another braking issue. Sporadically when I start the car and the engine has not come one and the car is only using battery, the brakes seem to have no play in the pedal. The car starts to move and when I tap the breaks they just lock with a thud and the pedal goes all the way to the floor. I then re step on the brakes and they work properly and feel normal. This usually happens in my driveway or parking lots and my first reaction is that I hit something because the car slams to a stop.

- El Sobrante, CA, USA

Brakes on 2010 Prius sometimes are "jerky". the pedal feels different and I require less or more pressure to get the car to brake. Occasionally when I press the brake the car jerks to a stop instead of a slow, controlled stop. I have been driving for over 20 years & the feeling is similar to how I felt in learning to drive when I didn't know how much pressure to use on the brake pedal. Bought car in October 2009 - problem noted about 10 times since that date.

- Niceville, FL, USA

We purchased a 2010 Prius in June and took it in for servicing in December. At that time we reported exactly the same problem that is now in the news -- when braking at low speed the vehicle occasionally lurches forward for an instant before slowing down. At the time we reported it, the dealer said that it was just the transition from electric to gas at the moment we applied the brakes. It now appears to be a more serious problem so I am writing to add our experience to your files. This problem does not happen often, but it is unsettling when it does since the driver does not expect the car to accelerate, even momentarily, during braking. In a tight situation or heavy traffic, this could easily cause an accident. So far when it has happened, there have been no consequences, but it is something we worry about. The date below is the date we reported the problem to our Toyota dealer.

- Piedmont, CA, USA

Three separate occasions of momentary loss of braking going over rough surface (two different locations) on dry asphalt. Each time the braking resumed after a short moment, as the brake pedal was kept pressed. When the brakes went out, it felt as if the car started lurching forward, causing momentary panic with the driver and the passengers. Luckily there was still time to get to a complete stop before impact.

- Moraga, CA, USA